On Thu, Jul 04, 2024 at 02:27:16PM GMT, Liam R. Howlett wrote:
> From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>
>
> Instead of shifting the length by PAGE_SIZE, use PHYS_PFN. Also use the
> existing local variable everywhere instead of some of the time.
>
> Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
> ---
> mm/mmap.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/mm/mmap.c b/mm/mmap.c
> index 0c334eeae8cd..b14da6bd257f 100644
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -2935,7 +2935,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
> struct mm_struct *mm = current->mm;
> struct vm_area_struct *vma = NULL;
> struct vm_area_struct *next, *prev, *merge;
> - pgoff_t pglen = len >> PAGE_SHIFT;
> + pgoff_t pglen = PHYS_PFN(len);
> unsigned long charged = 0;
> struct vma_munmap_struct vms;
> struct ma_state mas_detach;
> @@ -2955,7 +2955,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
> * MAP_FIXED may remove pages of mappings that intersects with requested
> * mapping. Account for the pages it would unmap.
> */
> - if (!may_expand_vm(mm, vm_flags, (len >> PAGE_SHIFT) - nr_pages))
> + if (!may_expand_vm(mm, vm_flags, pglen - nr_pages))
> return -ENOMEM;
>
> if (unlikely(!can_modify_mm(mm, addr, end)))
> @@ -2990,7 +2990,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
> * Private writable mapping: check memory availability
> */
> if (accountable_mapping(file, vm_flags)) {
> - charged = len >> PAGE_SHIFT;
> + charged = pglen;
> charged -= nr_accounted;
> if (security_vm_enough_memory_mm(mm, charged))
> goto abort_munmap;
> @@ -3149,14 +3149,14 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
> if (vms.nr_pages)
> vms_complete_munmap_vmas(&vms, &mas_detach);
>
> - vm_stat_account(mm, vm_flags, len >> PAGE_SHIFT);
> + vm_stat_account(mm, vm_flags, pglen);
> if (vm_flags & VM_LOCKED) {
> if ((vm_flags & VM_SPECIAL) || vma_is_dax(vma) ||
> is_vm_hugetlb_page(vma) ||
> vma == get_gate_vma(current->mm))
> vm_flags_clear(vma, VM_LOCKED_MASK);
> else
> - mm->locked_vm += (len >> PAGE_SHIFT);
> + mm->locked_vm += pglen;
> }
>
> if (file)
> --
> 2.43.0
>
Maybe I should literally look ahead before making comments :)) thanks for
reading my mind and doing what I asked though! ;)
However I don't think you've fixed the duplication of PHYS_PFN(vm_end -
vm_start) in count_vma_pages_range() - still worth doing I think.
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
